import { RouteReuseStrategy, ActivatedRouteSnapshot, DetachedRouteHandle } from '@angular/router';

export class CustomReuseStrategy implements RouteReuseStrategy {

  public static handlers: { [key: string]: DetachedRouteHandle } = {};

  /** 删除缓存路由快照的方法 */
  public static deleteRouteSnapshot(path: string): void {
    const name = path.replace(/\//g, '_');
    if (CustomReuseStrategy.handlers[name]) {
      delete CustomReuseStrategy.handlers[name];
    }
  }

  /**
   * 删除所有路由复用，一般用于当前用户退出时
   * @param path
   */
  public static deleteALLRouteSnapshot(): void {
    CustomReuseStrategy.handlers = {};
  }


  /** 表示对所有路由允许复用 如果你有路由不想利用可以在这加一些业务逻辑判断 */
  shouldDetach(route: ActivatedRouteSnapshot): boolean {

    if (route.routeConfig['path'] === 'login') {
      CustomReuseStrategy.handlers = {};
    }
    // 在缓存中有的都认为允许还原路由
    let ret = !!route.routeConfig && !CustomReuseStrategy.handlers[route.routeConfig.path];
    return ret;
  }

  /** 当路由离开时会触发。按path作为key存储路由快照&组件当前实例对象 */
  store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
    let key = this.getRouteUrl(route);
    // 2020/05/28 王志朋追加 首页和其他页面切换时，地图异常问题
    if (key != '_wel_home') {
      CustomReuseStrategy.handlers[key] = handle;
    }
  }

  /** 若 path 在缓存中有的都认为允许还原路由 */
  shouldAttach(route: ActivatedRouteSnapshot): boolean {
    //console.debug('shouldAttach======>', route);
    return !!CustomReuseStrategy.handlers[this.getRouteUrl(route)];
  }

  /** 从缓存中获取快照，若无则返回nul */
  retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
    if (!route.routeConfig) { return null as any; }
    if (route.routeConfig.loadChildren) {
      Object.keys(CustomReuseStrategy.handlers).forEach(key => delete CustomReuseStrategy.handlers[key]);
      return null as any;
    }
    if (!CustomReuseStrategy.handlers[this.getRouteUrl(route)]) {
      return null;
    }

    return CustomReuseStrategy.handlers[this.getRouteUrl(route)];
  }

  /** 进入路由触发，判断是否同一路由 */
  shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
    //console.debug('shouldReuseRoute======>', future, curr);
    return future.routeConfig === curr.routeConfig &&
      JSON.stringify(future.params) === JSON.stringify(curr.params);
  }

  /** 使用route的path作为快照的key */
  getRouteUrl(route: ActivatedRouteSnapshot) {
    const path = route['_routerState'].url.replace(/\//g, '_');
    return path;
  }

}
